SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b8eee8e6a07f0493d2265e01841851c1a36d603d67df9e8e33907295928a61c' 
  AND token = 'yxh2Pj/RR/uEIMk8w3+WA3IIS8NcyOHgbYLYLQlVDHs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}